12109 has 2 divisors, whose sum is σ = 12110. Its totient is φ = 12108.

The previous prime is 12107. The next prime is 12113. The reversal of 12109 is 90121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12100 + 9 = 110^2 + 3^2 .

It is an emirp because it is prime and its reverse (90121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12109 - 2¹ = 12107 is a prime.

Together with 12107, it forms a pair of twin primes.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6054 + 6055.

It is an arithmetic number, because the mean of its divisors is an integer number (6055).

12109 is a Friedman number, since it can be written as 110^2+9, using all its digits and the basic arithmetic operations.

2¹²¹⁰⁹ is an apocalyptic number.

It is an amenable number.

12109 is a deficient number, since it is larger than the sum of its proper divisors (1).

12109 is an equidigital number, since it uses as much as digits as its factorization.

12109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 12109 is about 110.0409014867. The cubic root of 12109 is about 22.9633948288.

It can be divided in two parts, 12 and 109, that added together give a palindrome (121).

The spelling of 12109 in words is "twelve thousand, one hundred nine".